Conventionally, a switch for power tools of this kind is provided with several separate contact units for turning on and off power, speed control, and reversing the rotational direction of the motor by switching over the polarity of the motor, for instance, as shown in Japanese patent application No. 62-288228.
However, according to such contact units, each contact unit must be provided with a separated return spring for its moveable contact piece, and the resulting increase in the number of component parts presented a major difficulty in simplifying the construction and assembly of the switch.
Further, since operation of the reversion switch over lever was carried out without producing any feel, the operator was prone to have doubt as to the accuracy of operation, and it has been desired to improve the tactile feel of its operation in order to improve the operability and reliability of the switch.